Background: I am a semi-pro photographer looking for additional local short-term storage solution aside from my HP Media Smart Server (more long term limited need to access for editing). I am using the WD Dard Drive with a Dell Inspiron Desktop using USB 2.0 under Windows 7 (64 bit).
Western Digital is a reputable brand for all types of storage solutions. This WD drive installed quickly and painlessly; even the packaging is easy to deal with. WD includes a longer than standard USB cable, which was a really nice surprise. The drive IS NOT powered by USB and requires an electrical outlet nearby. NOTE: I strongly recommend you do not install the typical WD software. Instead, rely on backup software already on your OS or Microsoft's Sync Toy (I use to replicate my client photo sessions folders). This will allow you to avoid conflicts I always seem to encounter. WD software is not needed and the drive is pre-formatted. Literally, "plug and play." WD provides little hard copy documentation. However, everything you need is provided (startup poster). For some reason, people are still hung up on the lack of documentation. Everything you need is in the box and any information you could want is on their site. IMHO, the less paper, the better.
Upon installation, the drive was immediately recognized by my computer. The drive is incredibly quiet with no fan noise and I have to look at the light on the front of the unit to determine if it is on unless I have my drives open on my computer. The drive sits upright (or you can lay it down and stack drives) and is barely noticeable next to my computer. The drive comes with a Kennsington lock slot and the ability to password protect drive contents.
Speed: I am not a test freak so my tests are based on practical usage. I transferred 25 GB of Raw image files (about 12-18 mb a piece) in about 15 minutes @ USB 2.0. The drive did not hesitate once during this process (straight copy over as opposed to SyncToy replication). My system backups seem slower, though acceptable. There is no noticeable adverse impact on computer performance when using the drive, so you can easily continue working on other tasks. As I sometimes edit large Raw files directly on the WD drive, I can comment that the speed was more than acceptable for my purposes (using Nikon Capture NX2 and Photoshop CS5). However, pro-photographers would probably need a faster solution.
In summation, I trust WD and find this drive a great solution for my needs. I recommend this drive. If anything changes, I will update my review.